I think you want to say, "Well, I often hear Americans say those words." Are you nuts? = Are you crazy? "nuts" and "crazy" are informal words. A more formal word for "nuts" or "crazy" is "insane". a "jerk" is a either a very foolish or stupid person, or a person for whom you feel contempt.

"Are you nuts!?" = "Are you crazy/insane?!" "Jerk" <that is an insult meaning you are foolish/stupid and/or rude. :) by the way "amereican" is spelled wrong, it is "American".

what does "Are you nuts" and "jerk" ? well i often hear does words to amereican What does "Are you nuts" and "jerk" mean? I often hear Americans use these expressions. "Are you nuts" means are you crazy, mad, insane, out of your mind etc , A "jerk" is someone who has acted badly or in a mean manner. Jerk=asshole.